This invention relates to dynamic user management for time shared computer systems.
In a time shared computer system, each user can get pro-rated computer resources over some interval of time. These resources are various classes of memory and disk storage and, in multi-processor systems, a share of one or more processors. These resources are limited, however, and not all users can be active or even contained in memory at any given time. The problem addressed in this invention is how to allocate the computer resources at any given time for the set of users.
We note that currently, each user has a priority and is given a fixed slice of computer time in which he can do his processing, and then has an inactive period of time during which other users are active. The frequency of user activation is determined by the given user""s priority. There is no optimal discipline for replacement of one or more users in memory by a newly activated user.
We have now discovered a novel method for allocating computer resources specifically, dealing in particular with the task of determining which set of users are to be contained in memory at any given time in order to maximize the performance of the time-shared computer system.
The novel method is suitable for determining a set of users which are to be contained in a main memory at a given time, the method comprising the steps of:
(i) tracing for each active user a usage of computer resources;
(ii) evaluating for each inactive user an expected usage of computer resources;
(iii) identifying a set of users to be resident in main memory at a given time; and
(iv) employing a user measure based upon the usage of computer resources based upon input from steps (i)-(iii), for determining a dynamic user replacement plan for maintaining a set of users in main memory at a given time.